What is the difference between linear feet and board feet?

Linear feet measures only length. Board feet measures volume (thickness in inches × width in inches × length in feet ÷ 12). One linear foot of a 2×8 equals 1.33 board feet. Hardwood is sold by the board foot; softwood framing is sold by the piece or linear foot. A linear foot is just a foot of length, regardless of dimensions. A board foot is 144 cubic inches of lumber. The two units describe different things — linear feet for length-based pricing (most softwood framing), board feet for volume-based pricing (most hardwood). To convert: board feet = (nominal thickness × nominal width × length in feet) ÷ 12. A 2×8×12 ft board = (2 × 8 × 12) ÷ 12 = 16 board feet, which is 12 linear feet. The conversion factor changes with every dimension combination.

Why are softwood and hardwood priced in different units?

Historical convention. Softwood framing is mass-produced in standard sizes — selling per piece is simpler at the volume of a typical contractor order. Hardwood is sold at small mills in mixed widths and lengths — the only fair way to price it is by volume (board feet), since a 4-inch wide board and an 8-inch wide board of the same length are not equivalent.

How do I quickly estimate board feet from linear feet?

For 1× lumber, multiply the width by length and divide by 12 (so 1×6 × 10 lf = 5 bd-ft). For 2× lumber, multiply by 2 (2×6 × 10 lf = 10 bd-ft). For 4×, multiply by 4. The shortcut: width in inches × thickness factor × length in feet ÷ 12.

Does the price per linear foot include the wider/thicker premium?

Yes — when lumber is priced per linear foot, the per-foot cost varies by dimension. A 2×4 might be $0.50/lf while a 2×12 of the same species and grade is $2.50/lf. The per-foot price already accounts for the volume difference.

Why does engineering use board feet for spans?

Span tables are usually expressed in piece-based language ("a 2×10 spans 16 feet at 16 o.c."), not board feet. Board feet shows up in specs for total ordered volume on big jobs (timber framing, custom millwork) where the contractor commits to a quantity in advance.

Linear Feet vs Board Feet (Conversion + Examples)

Linear feet to board feet conversion (per 1 linear foot)
Lumber size	Board feet per linear foot
1×4	0.33 bd-ft
1×6	0.50 bd-ft
1×8	0.67 bd-ft
1×10	0.83 bd-ft
1×12	1.00 bd-ft
2×4	0.67 bd-ft
2×6	1.00 bd-ft
2×8	1.33 bd-ft
2×10	1.67 bd-ft
2×12	2.00 bd-ft
4×4	1.33 bd-ft
4×6	2.00 bd-ft
6×6	3.00 bd-ft

Linear feet to board feet conversion (per 1 linear foot)

Lumber size

Board feet per linear foot

1×4

0.33 bd-ft

1×6

0.50 bd-ft

1×8

0.67 bd-ft

1×10

0.83 bd-ft

1×12

1.00 bd-ft

2×4

0.67 bd-ft

2×6

1.00 bd-ft

2×8

1.33 bd-ft

2×10

1.67 bd-ft

2×12

2.00 bd-ft

4×4

1.33 bd-ft

4×6

2.00 bd-ft

6×6

3.00 bd-ft

How to calculate it yourself

Board feet = (nominal thickness in inches × nominal width in inches × length in feet) ÷ 12. Linear feet = length in feet only. To go from linear to board feet, multiply by the factor in the chart above. Hardwood is always priced per board foot; softwood framing is usually priced per piece or per linear foot but engineering specs may call out board feet.

Common scenarios

Buying framing lumber (priced by piece)

You need 30 2×4×8 ft studs. Lumberyard prices each piece individually ($4-6/each in 2026). Total: $120-180. The "board feet" of this order is 30 × 5.33 = 160 bd-ft, but you would only quote that on a custom or contract order.

Buying hardwood (priced per board foot)

Custom millwork project needs 6/4 × 8" wide × 8 ft long red oak boards. One board = (1.5 × 8 × 8) ÷ 12 = 8 bd-ft. At $7/bd-ft retail, each board is $56. For 10 boards: 80 bd-ft × $7 = $560.

Mixed quote (deck project)

Deck framing (2×8 joists) priced per linear foot: 200 lf × $3/ft = $600. Decking (5/4×6 PT) priced per linear foot: 600 lf × $1.80/ft = $1,080. Hand-rail cap (custom 2×4 cherry) priced per board foot: 50 bd-ft × $9/bd-ft = $450. Mixed-unit quotes are common — make sure you know which unit each line item uses.

Linear Feet vs Board Feet: What is the Difference?

At a glance

How to calculate it yourself

Common scenarios

Buying framing lumber (priced by piece)

Buying hardwood (priced per board foot)

Mixed quote (deck project)

Frequently asked

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At a glance

How to calculate it yourself

Common scenarios

Buying framing lumber (priced by piece)

Buying hardwood (priced per board foot)

Mixed quote (deck project)

Frequently asked

Related questions

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Drywall Calculator

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